NABCEP Site Assessment 5 — Questions and Answers
Question 1: What does the term 'solar window' refer to in the context of a site assessment?
- A skylight installed to maximize natural daylighting
- The unobstructed arc of sky through which the sun travels and delivers usable solar energy (Correct answer)
- The time of year when net metering credits are highest
- The orientation range in which modules may be installed per code
Correct answer: The unobstructed arc of sky through which the sun travels and delivers usable solar energy
The solar window is the unobstructed portion of the sky through which the sun passes during productive hours, and obstructions within it reduce energy production.
Question 2: A site assessor identifies that the proposed location is in a fire hazard severity zone. What additional code requirement typically applies?
- All modules must be bifacial
- Setbacks from ridges and edges must be maintained for firefighter access (Correct answer)
- Only DC-optimized systems are permitted
- Permits are not required in fire hazard zones
Correct answer: Setbacks from ridges and edges must be maintained for firefighter access
California and other jurisdictions require specific setback distances from roof edges, ridges, hips, and valleys in fire hazard zones to allow safe firefighter access and ventilation.
Question 3: During a site visit, the assessor measures an azimuth of 195° for the best roof surface. How would you characterize this orientation for a US installation?
- Slightly west of due south, generally acceptable with minor energy penalty (Correct answer)
- Due east, poor for solar production
- Due north, not suitable for solar
- Slightly east of due south, ideal orientation
Correct answer: Slightly west of due south, generally acceptable with minor energy penalty
195° azimuth is 15° west of due south (180°); this slightly west-of-south orientation is generally acceptable and may even benefit time-of-use customers who need afternoon production.
Question 4: What is the primary purpose of measuring the distance from the proposed array to the main electrical panel during site assessment?
- To determine module efficiency required
- To calculate wire sizing and voltage drop for DC and AC conductors (Correct answer)
- To assess shading from the building itself
- To estimate system weight on the roof
Correct answer: To calculate wire sizing and voltage drop for DC and AC conductors
Conductor length between the array and panel determines resistance and voltage drop, which must be kept within code limits (typically ≤3%) and influences wire gauge selection.
Question 5: An assessor finds that a customer's property is subject to an easement. Why is this relevant to a solar installation?
- Easements affect only underground utility connections
- An easement may restrict structures or installations within the easement area, potentially limiting array placement (Correct answer)
- Easements always grant additional rights to install solar
- Only commercial properties have easements
Correct answer: An easement may restrict structures or installations within the easement area, potentially limiting array placement
Easements grant third-party rights over portions of a property, which can restrict the placement of structures like solar arrays within that area.
Question 6: When conducting a site assessment for a battery-paired solar system, which additional factor must be evaluated compared to a PV-only system?
- Module bifaciality requirements
- Available indoor or conditioned space meeting temperature, ventilation, and clearance requirements for battery installation (Correct answer)
- Higher azimuth accuracy requirements
- Reduced interconnection requirements from the utility
Correct answer: Available indoor or conditioned space meeting temperature, ventilation, and clearance requirements for battery installation
Battery systems have specific installation environment requirements including temperature range, ventilation for off-gassing, and minimum clearances that must be verified during site assessment.
Question 7: A site's peak sun hours (PSH) value is determined primarily by which data source during a site assessment?
- The customer's historical utility bills
- NASA, NREL PVWatts, or similar solar resource databases for the geographic location (Correct answer)
- The local building department's solar map
- The manufacturer's module datasheet
Correct answer: NASA, NREL PVWatts, or similar solar resource databases for the geographic location
Peak sun hours are derived from long-term solar irradiance databases such as NREL's PVWatts or NASA's SSE, which provide location-specific solar resource data used in energy production estimates.
NABCEP Site Assessment 5
What does the term 'solar window' refer to in the context of a site assessment?